1. Field of the Invention
The present invention relates to a lubricating structure of a transmission adapted to supply lubricating oil to an area around a shaft, which rotates in a transmission, through an internal space of the shaft.
2. Description of the Related Art
There has conventionally been known a transmission adapted to supply lubricating oil from an oil passage provided in a case of the transmission to an oil passage in a shaft, which rotates in the transmission and to distribute the lubricating oil to a clutch, a synchronization mechanism and the like through a plurality of lubrication holes provided in the shaft.
For example, Japanese Patent Application Laid-Open No. 2007-24234 discloses a lubricating device proposed to correct the imbalance of lubricating oil in a transmission. In the lubricating device, a pipe is inserted from one end into an oil passage in the shaft over the full length of the oil passage, and the pipe is provided with a plurality of lubrication holes that penetrate from the inner peripheral surface of the pipe to the outer peripheral surface thereof.
The lubricating oil supplied to the one end in the pipe flows out of each lubricating hole in the pipe to be distributed to an area around the shaft through each corresponding lubricating hole in the shaft. This arrangement corrects an imbalanced distribution amount of the lubricating oil in the lengthwise direction of the shaft regardless of the rotational speed of the shaft.
However, there are some cases where supplying an even distribution amount of lubricating oil over the full length of a shaft is not appropriate. For example, in the case of a transmission having a clutch, which requires abundant lubricating oil, disposed in the vicinity of one end of a shaft to which the lubricating oil is supplied, it is necessary to supply more lubricating oil to the vicinity of the one end of the shaft than that supplied to the remaining mechanisms.